material prices

when gas hit $4.00 per gallon 2 years ago and it cost $120.00 a barrel, material costs shot thru the roof(excuse the pun). Then gas dropped back to 70-75 per barrel for over a year. But they didn't reduce our material costs. Now gas is going up agin and their talking about more material increases. I don't understand why we didn't get a discount when oil dropped by 45%. I think the suppliers and mfger's are taking advantage of us, not just the oil companies.

Ive been saying that all along,you have only 6 major shingle manufactures now,why? Because like the oil companys its easier to manipulate the market and control pricing.